1. Field of the Invention
The present invention relates to a door locking handle assembly of a pull-out and side-swinging lever-action type. The door locking handle assembly is used in a plugboard box and the like. In operation, the retractable handle of the assembly is pulled out of its casing and side-swung through a predetermined angle to permit a catch plate of the assembly to be free from a receiving portion of a stationary frame element.
2. Description of the Prior Art
In a conventional door locking handle assembly of a pull-out and side swinging lever-action type disclosed in Japanese Utility Model Laid-Open No. Sho 63-198764: a cylinder portion is provided in a base-end portion of a casing fixedly mounted on a door; a locking shaft is totalably mounted in the cylindrical portion in an insertion manner; a catch plate is fixedly mounted on a rear-end portion of the locking shaft; a retractable handle folds into a front concave portion of the casing, and has its base-end portion pivoted to a front-end portion of the locking shaft through a cross pivot; a biasing spring for swingably biasing the retractable handle in its projecting direction on the cross pivot, the biasing spring being mounted between the locking shaft and the handle; a locking aperture is provided in a finger-engaging projecting portion of a front-end portion's rear surface of the handle; a lock unit is fixedly embedded in a lock-receiving portion provided in a front-end portion of the casing; and, a latch element is so arranged as to be interlocked with a rotor of the lock unit, and is biased forward towards the finger-engaging projecting portion by a return spring to have a front-end portion of the latch element engaged with the locking aperture so that the handle is locked up in its retracted position.
However, in the conventional door locking handle assembly described above, there is a fear that the front-end portion of the handle hits a user's fingers. Namely, when the user inserts a key into the lock unit to have its rotor rotated in an unlocking direction thereof, the latch element slidably moves backward to be free from the locking aperture of the handle, so that the handle is projected forward and turned under the influence of a resilience force exerted by a biasing spring, whereby the front-end portion of the handle hits the user's fingers.
In order to prevent the handle from hitting the user's fingers, it is sufficient to dispose the lock unit in a position far away from the front-end portion of the handle. However, naturally, this causes the entire length of the casing to increase.
In order to set a sufficient interval between the lock unit and the handle without increasing the entire length of the casing, it is sufficient to decrease the handle in length. However, when a grip portion of the handle is extremely shortened, the handle is impaired in operability. Consequently, such shortening of the grip portion of the handle is not adequate.
When the catch plate is converted from a left-hand turning/stopping type to a right-hand turning/stopping type, or vice versa, i.e., when a mounting position of the locking handle assembly is moved from the door's left side to the door's right side, or vice versa, it is necessary to change the catch plate in its orientation. However, in this conventional locking handle assembly, when the catch plate is dismounted from the locking shaft, the locking shaft moves forward along the cylindrical portion to permit both the handle and the locking shaft to drop out of the casing. Consequently, the user must hold the locking shaft to prevent the same from moving forward when he changes the orientation of the catch plate in mounting operation of the assembly, which is very cumbersome.
Further, when the catch plate is smaller in thickness than a predetermined value, the locking shaft may move forward by a distance corresponding to a difference between the thickness of the catch plate and the predetermined value. This causes the base-end edge portion of the handle to engage with an edge portion of the front concave portion of the casing, which makes the base-end edge portion of the handle unworkable by jamming.